Geology SEDIMENTARY ROCK
A mudstone is composed of particles ranging in size from than ____ mm to ____mm
.0035-.0625
Sand is cohesionless sediment ranging in size between ____ mm and _____ mm
.0625-2
Beds are thicker than _____ cm.
1 cm.
The process of reducing pore space by depositing younger sediments on top of older material is referred to as:
Compaction.
what is the significance of cross beds and ripples
Cross beds and ripples are sedimentary structures that indicate the general direction of wind or water currents during deposition.
Physical weathering?
The mechanical breakdown by plants, animals, abrasian, freezing/thawing
What does sorting refer to?
The range in grain size of sediment in a given sample. If it's well-sorted, they'll all be about the same size.
What would you call a carbonate rock composed of calcite and abundant pieces of clam shells
bioclastic limestone
A sedimentary rock composed of angular gravel is called a
breccia
Sand that is cemented with calcite is called
calcareous sandstone. or just sandstone.
a common mineral found in carbonate sedimentary rocks is
calcite
When rivers enter large bodies of standing water they typically debouche their loads
deltas
A dolostone is composed mostly of the mineral __________.
dolomite
what do you call accumulations of sand that are the result of blowing wind?
dunes or sand dunes
Oolitic limestone is an example of an organic carbonate rock.
false
Laminations are thicker than beds. True or false?
false.
The current adjacent to the cut bank moves ________than the current along the point bar side
faster
> 25% feldspar The ratio of feldspar to feldspar + rock fragments is > 50% matrix is > 15%
feldspathic wacke
All clastic sedimentary rocks display a ________ or _______ texture.
fragmental, clastic.
Grains of sand make up one component of a sandstone: ________ Grains smaller than the sand make up: _________
framework. Matrix.
> 25% feldspar The ratio of feldspar to feldspar + rock fragments is > 50% matrix is <15%
lithic arenite
Classic sedimentary rocks are composed of ______ and _____ _________ derived from pre-existing material
minerals, rock fragments
Alluvial fans develop at the base of
mountain fronts
If a sandstone inclues less than 15% matrix, and is composed of > 90% quartz.
quartz arenite
A mound shaped feature composed chiefly of the calcareous remains of sedentary marine organisms is a
reef
NaCl when found in rock form is referred to as ______ ___________
rock salt.
The angularity of the edges and corners of grains in a sedimentary rock is referred to as
rounding.
Whats the difference between shale and fissility?
shale exhibits fissility while a mudstone does not.
The cement in a sandstone is typically the result of the precipitation of minerals like quartz and calcite from....
solutions.
Sediment always carried above the river bed in the moving current is classified as
suspended load
Where are submarine fans found?
they are common features of continental rise environments
Graded beds are the result of deposition by
turbidity currents.
The pores of clastic sedimentary rocks are the _______ between grains
voids or empty spaces.
In general the greater the distance sediment is transported the more _________ and _______ sediment becomes.
well-sorted and rounded. Think of river.
how would you describe the property of fissility?
when you hit with rock hammer, separates into two parallel sheets
Major agents of erosion
wind, water, ice
Formations are generally considered to be mappable on a scale of
1:24,000
Gravels (including pebbles) are pieces of older rock material greater than
2 mm.
What is a contact?
A contact is a 3D surface separating rocks of different lithological aspect.
The largest clast size in the range of gravel is
BOULDER
Chemical weathering?
Chemical alteration of weathered material brought on by reactions with the hydrosphere, biosphere, and atmosphere
What do mud cracks signify?
The evaporation of water and the drying out of sedimentary environment.
In the following illustration what are a b c d and e, from left to right...
a) shelf b) shelf-slope break c) slope d) rise e) abyssal plain
In the following illustration fill in the missing labels a). big ones b). little ones in spaces
a). framework grains b). matrix.
Strips of sand and gravel lying above sea level and paralleling the adjacent coastline but separated from it by a narrow body of water are called
barrier islands
A _____ is a strip of sand and gravel extending from the low- to high-tide line
beach
Sediment dragged or pushed or bounced along river bed is.....
bed load
An example of a siliceous chemical rock is
chert.
What is the name of the clastic sedimentary rock composed of particles less than .0035 mm?
claystone
Siltstones are coarser grained than
claystones
Rock that is the result of compaction of variably decayed plant matter is referred to as.....
coal.
Microfossils found in chalk
coccolithophore
A sedimentary rock composed of rounded gravel is called a
conglomerate